Absorbent article and method of manufacturing article

ABSTRACT

An absorbent article comprising a main body having a waist hole and a pair of leg holes, an elastic waist portion disposed along the, waist hole and a leg gather disposed along each of the leg holes. The main body comprises a front section and a rear section joined to each other in a crotch region and side regions of the main body. The front section has at least one constituent element whose property is different from that of the corresponding element of the rear section. The absorbent article is fully responsive to a variety of article configurations or constructions which require the front and rear sections to function differently or individually. A method for manufacturing such an absorbent article is also disclosed.

BACKGROUND OF THE INVENTION

The present invention relates to an absorbent article such as an infantdiaper or an adult diaper, and further to a method for manufacturingsuch an absorbent article.

Absorbent articles, particularly infant and adult diapers includeseparate-type diapers and integral-type or tapeless-type diapers. Theseparate-type diaper is constructed to be separable from opposite sidesof its waist region so that it can be developed into a flatconfiguration, and includes fastening tapes for releasably connectingfront and rear waist regions of the diaper when applying the diaper to auser's body. The tapeless-type diaper is a pant-type diaper whichincludes a waist hole and a pair of leg holes. Both the separate-typeand the tapeless-type diapers include a main body which comprises aliquid impermeable backsheet, a liquid permeable and hydrophobictopsheet superposed onto the backsheet and an absorbent core interposedbetween the topsheet and the backsheet. The main body is configured toinclude an elasticized waist portion and a pair of leg holes.Especially, the tapeless-type diapers have recently gained increasedacceptance from consumers for their advantageous characteristics ofstability during use and applicability to standing users, which are bestsuited for their application to infants who have just started walking.

Conventional tapeless-type articles include pant-type and supporter-typearticles. One example of the pant-type article is illustrated in JPA No.3-82467 wherein a backsheet, formed of an elastic non-woven fabric,covers both of front and rear sections of the diaper. U.S. Pat. No.4,938,757 discloses a diaper typical to the supporter-type article whichincludes elastic side bands for connecting side ends of a front sectionand side ends of a rear section.

When manufacturing, these articles, main bodies of the articles areassembled with their longitudinal direction being arranged either in amachine direction (MD) or in a cross-machine direction (CD), andintegrally-formed front and rear sections of each of the main bodies arethen bi-folded for side sealing of respective, opposite side endsthereof.

However, such manufacturing methods as mentioned above have certainlimitations in terms of productivity and feasibility to accommodatevarious article constructions. In order to improve the productivity ofthose articles, JPA No. 3-123551 proposes a method wherein a backsheetis placed on a bi-folded main part comprising a topsheet and anabsorbent core placed thereon prior to heat-sealing along wing and legportions of an article.

It has been recognized that such conventional tapeless-type absorbentarticles are unable to fully accommodate various product features soughtfor more desirable article configurations during use or moregener-specific article specifications. For example, a desirable locationof a maximum absorbing capacity is different between diapers for mailand female. In order to meet such needs, an absorbent core is requiredto have different absorbing capacities, therefore different quantitiesof absorbent material between opposite sides of a crotch portion of anarticle.

However, such provision of different quantities of absorbent materialbetween front and rear sides of the absorbent body consequently createsdifferences in thickness and rigidity between a front side and a rearside of the absorbent body exactly along its center line. When thefolding of the absorbent body is not made at a correct position, thetopsheet superposed on the absorbent body is also hi-folded at anoff-center position so that opposite ends of the topsheet are misalignedto form an irregular waist profile after heat-sealing thereof to theabsorbent core. This reduces the product value of the resulting article.

In order to minimize production of such inferior articles, it isrequired to effect exact alignment of opposite ends of the topsheet whenit is bi-folded. It is, however, difficult to hold such flexiblematerial correctly in a desirable position by present commerciallyavailable equipment, which results in an increased equipment cost andreduced productivity as well.

It is an object of the present invention to provide a tapeless-absorbentarticle which is capable of eliminating the above-describeddisadvantages of conventional tapeless articles that are generallycaused by the necessity of bi-folding of absorbent cores.

Another object of the present invention is to provide a method formanufacturing such an improved absorbent article.

SUMMARY OF THE INVENTION

The present invention provides an absorbent article which comprises amain body having a waist hole and a pair of leg holes, an elastic waistportion disposed around the waist hole, and an elastic leg gatherdisposed around each of the leg holes. The main body comprises a frontsection and a rear section. The front and rear sections have differentconstructions from each other and are connected to each other in acrotch regions and side regions of the article. Each of the front andrear sections comprises a backsheet, a topsheet disposed inwardly of thebacksheet, and an absorbent body interposed between the topsheet and thebacksheet.

Because the absorbent article of the present invention has the front andrear sections which have respective individual constructions formed ofrespectively selected, desirable materials, the article is capable ofaccommodating various features so that the front and rear sections areallowed to function substantially independently from each other.

When the absorbent article of the present invention is used as a diaperfor infants who frequently lie with their faces down, the front sectionmay comprise a highly absorbent element containing a combination ofpulps and superabsorbent materials and the rear section may comprise athin and expansive absorbent element. This permits front and rearportions of the article to exhibit urine absorbent capacity and capacityof treating fecal material, respectively.

It is preferable that the front section having high absorbing capacitieshas an overall dimensionally stable construction including an absorbentbody and the rear section is provided with elastic materials to be moreflexible.

The front section may comprise a topsheet formed of a hydrophobic,bulky, fine-mesh sheet treated to be hydrophilic and the rear sectionmay comprise a topsheet formed of a hydrophilic coarse mesh sheet sothat the above-mentioned urine absorbent capacity and the capacity oftreating fecal material thereof can be fully exhibited.

Furthermore, the front section may comprise a backsheet formed of ahighly liquid-resistant film and the rear section comprises a backsheetformed of a highly air-permeable film so that improved comfort isprovided to users during use. Different coloring or patterning of thehacksheet between the front and rear sections permits users to identifythe front and rear portions of the absorbent article at a glance.

As described above, the method of assembling the front and rear sectionsseparately from each other and thereafter joining them provides variousadvantages in designing a variety of absorbent article constructions.However, there exist problems to be solved since the absorbent articlehas in its crotch region the securement region.

A first problem comes from the securement of the front and rear portionsof the absorbent body. The problem needs to be solved by joining themwithout any defects. A second problem comes from the securement of frontand rear portions of the gather. For example, the simple securement ofthe front and rear portions may disturb continuities thereof. It mayprevent the standing leg gathers from standing up in the securementregion. Therefore, it becomes important to solve the problem bymaintaining continuity of the front and rear standing gather portions.

Now the securement of the front and rear absorbent body portions will beexplained. Each of the front and rear sections has a central regionincluding a topsheet, a backsheet and an absorbent body, and a marginalend including the topsheet and the backsheet. The respective marginalends of the front and rear sections are joined together to form a tab.Those marginal ends may be joined to each other typically byheat-bonding. The heat-bonding may be effected by a plurality of linesor by relatively wide bands to obtain stable securement results. It ispreferred that the ends including the absorbent bodies are previouslyjoined to each other by hotmelt adhesives before the marginal ends areheat-bonded to each other. This provides improved, urine leakageprotection.

In order to obtain more stable securement, it is advantageous that areinforcing member is additionally attached to the securement region.One approach is to provide a tape-like reinforcing member along aboundary in a crotch securement region of the front and rear sections.Such a reinforcing member needs to be liquid-permeable and preferablycomprises a highly liquid-permeable porous non-woven fabric.

Another effective method is to insert a heat-sealable sheet between thefacing top surfaces of the front and rear sections. The heat-sealablesheet is bonded to the front and rear sections simultaneously as theyare heat-bonded to form the crotch securement region. In such an event,while one end of the heat-sealable sheet is bonded to the securementregion together with the topsheets and backsheets, another end thereofis unsecured to project upwardly like a petal in a central portion ofthe absorbent article. This projection portion serves to separate thefront portion from the rear portion of the article and has an effectivefunction to separate urine from fecal material. Accordingly, theprojecting portion may be preferred to as "a separating petal". Theseparating petal may comprise a heat-sealable film or non-woven fabric,preferably an elastic and heat-sealable elastomeric film or non-wovenfabric such as of ethylene vinyl acetate co-polymer (E.V.A.), styleneethylene butodiene stylene block co-polymer (S.E.B.S.),or styleneethylene propylene stylene block co-polymer (S.E.P.S.).

Now, the securement of front and rear standing leg gather portions willbe explained. As described above, when the front and rear sections areto be joined to form an integral absorbent article, it becomes one ofimportant requirements to maintain the continuities of the gatherportions in the crotch securement region. Especially, it is true whenthe standing gathers are incorporated in the article. The simplesecurement of the front and rear sections tends to prevent the standinggather portions from standing up in the crotch securement region.Therefore, suitable means needs to be implemented to maintain thecontinuities of the standing gather portions in the crotch securementregion.

According to the present invention, such problems are solved by thefollowing means. Prior to joining the front and rear sections, each ofthe strip members for forming the standing gather portions is secured atits lower edge to the topsheet by suitable bonding means, with its upperedge being unsecured thereto. Each of the strip members extendslongitudinally beyond the absorbent body to define the marginal endtogether with the backsheet in the crotch securement region. At thestage when the marginal ends of the front and rear sections are joinedto each other to form the tab, selected surface areas of the respectivestrip members of the front and rear sections are placed upon each other.The selected surface area of each strip member extends transversely toits full width and extends longitudinally from the tap portion toward aninner portion of the front or rear section beyond an outer edge of theabsorbent body. The selected surface areas of the respective stripmembers are bonded to each other by hotmelt adhesives.

The triangular bonded portion thus formed between the front and rearsections is referred to as "a cross-over flap" in the specification forconvenience of explanation. The cross-over flap formation causes thelength dimension of the upper edge of the strip member to be smallerthan that of the lower edge of the strip member. This difference inlength dimension causes the strip member to stand up from the topsheetto define the so-called standing leg gather.

The formed cross-over flap portion is connected to the topsheet portionthrough the tab so that it serves to support the standing gather.Accordingly, the cross-over flap portion has the function whicheffectively prevents the standing gather from moving a great dealinwardly or outwardly; especially from moving outwardly. In the eventthat the cross-over flap is joined to the aforementioned separatorpetal, it also serves to maintain the standing leg gather in asubstantially upright position. The substantially upright standinggather defines a partition between front and rear portions of thearticle so that it serves as a separator to prevent urine and fecalmaterial from mixing with each other.

In the present invention, the elasticity of the gather is set to theminimum that permits the inner leg gather to snugly fit to a user'sbody. As the elasticity increases, the inner leg gather is more likelyto yield to the pressure exerted by the movement of the user or by theload of body exudates so that the gather experiences deformation whichsubsequently cause leakage of the body exudates. Suitable materials forthe strip member which forms the inner leg gather include a non-wovenfabric having suitable elasticity and flexibility and an elasticcomposite of a non-woven fabric and an elastic material. A typicalexample of the elastic non-woven fabric is the one manufactured bysubjecting a carded web containing highly heat-shrinkable conjugatefibers of polyesters or polypropylenes to high-pressure water jet andapplying heat to the resulting hydroentangled non-woven fabric. Typicalexamples of the elastic composite include a composite of a non-wovenfabric and an elastic film and an composite of a non-woven fabric andelastic meltblown fibers. As will be readily appreciated, the concept ofthe present invention is also applied to the inner leg gather ofconventional construction which includes an elastic material in its headportion and a non-woven fabric in its leg portion.

In accordance with still another aspect of the present invention, thereis provided a method for manufacturing an absorbent article whichcomprises a main body having a waist hole and a pair of leg holes, anelastic waist portion disposed along the waist hole and a leg gatherdisposed along each of the leg holes. The method comprises the steps ofproviding a topsheet, an absorbent body and a backsheet for assembling afront section, providing a topsheet, an absorbent body and a backsheetfor assembling a rear section, and placing the front section upon therear section for joining the front and the rear sections to form acrotch region and opposite side regions of the main body.

U.S. Pat. No. 4,427,408 discloses a method for manufacturing theabsorbent articles which places a front section upon a rear section forsecurement thereof. This method however prepares an integral pair offront and rear sections before bi-folding the pair of sectionslongitudinally or transversely, in contrast to the present method whichassembles the front and rear section separately and eliminates thenecessity of the bi-folding.

Prior to the placing, step, waist and lea elastics may be provided alongperipheries of the waist hole and the lea holes, respectively, to formthe waist gather and the leg gathers. A reinforcing step may be added tothe above steps to reinforce the crotch securement region.

The present invention further provides a method for manufacturing anabsorbent article which comprises a main body having a waist hole and apair of leg holes, an elastic waist portion disposed along the waisthole and a leg gather disposed along each of the leg holes. The methodcomprises the steps of providing absorbent bodies in predeterminedintervals between a longitudinally moving first continuous web and alongitudinally moving second continuous web to form a first assembly,providing absorbent bodies in predetermined intervals between alongitudinally moving third continuous web and a longitudinally movingfourth continuous web to form a second assembly, moving the firstassembly and the second assembly in the same direction for introducingthe first assembly upon the second assembly, heat-bonding the first andsecond assemblies to form the crotch regions and side regions of themain body, and cutting the first, second, third and fourth continuouswebs in the heat-bonded regions.

One of the important advantages of the present method is that a step ofbi-folding a member including a topsheet, a backsheet and an absorbentbody in a crotch region is eliminated because a front section and a rearsection of an absorbent article are separately assembled before they arejoined to each other in a crotch region and opposite side regions.Therefore, the present method is capable of eliminating the troublesomealignment of the front and rear sections necessitated by the bi-foldingto provide improved process efficiency and a reduced rate of productloss.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of an absorbentarticle in accordance with the present invention, partially cut away toreveal the inside structure;

FIG. 2 is a longitudinal cross-section view of the absorbent article ofFIG. 1;

FIG. 3 is a developed plan view of the absorbent article of FIG. 1 witha topsheet removed;

FIG. 4 is a partially cut-away perspective view of a second embodimentof an absorbent article in accordance with the present invention;

FIG. 5 is a longitudinal cross-sectional view of the absorbent articleof FIG. 4;

FIG. 6 is a developed plan view of the absorbent article of FIG. 4 witha topsheet removed;

FIG. 7 is a fragmentary longitudinal cross-sectional view of an elasticcomposite sheet suitable for use in an absorbent article of the presentinvention;

FIG. 8 is a partly cut-away perspective view of a third embodiment of anabsorbent article in accordance with the present invention;

FIG. 9 is a longitudinal cross-sectional view of the absorbent articleof FIG. 8;

FIG. 10 is a developed plan view of the absorbent article of FIG. 8 witha topsheet removed;

FIG. 11 is an enlarged cross-sectional view taken along a line A--A ofFIG. 10;

FIG. 12 is a developed plan view of a fourth embodiment of an absorbentarticle of the present invention with a topsheet removed;

FIG. 13 is an enlarged cross-sectional view taken along a line B--B ofFIG. 12;

FIG. 14 is a partly cut-away perspective view of a fifth embodiment ofan absorbent article in accordance with the present invention;

FIG. 15 is a longitudinal cross-sectional view of the absorbent articleof FIG. 14;

FIG. 16 is a developed plan view of the absorbent article of FIG. 14with a topsheet removed;

FIG. 17A is a partly cut-away perspective view with a magnified section17B illustrating a preferred embodiment of a joint construction betweena front section and a rear section;

FIG. 18A is a partly cut-away perspective view with a magnified section18B illustrating another preferred embodiment of a joint constructionbetween a front section and a rear section;

FIG. 19A is a partly cut-away perspective view with a magnified section19B illustrating still another preferred embodiment of a jointconstruction between a front section and a rear section;

FIG. 20 is a partly cut-away perspective view of still anotherembodiment of an absorbent article in accordance with the presentinvention;

FIGS. 21A, 211B, 21C illustrate a portion of the absorbent article ofFIG. 20 wherein 21A is a partly cut-away perspective view illustrating aleg gather portion, 21B is a view illustrating a tab portion formed inthe leg gather portion and 21C is a view illustrating an angle at whichthe leg gather stands up;

FIG. 22 is a partly cut-away perspective view of the absorbent articleshown in FIG. 20 as being in the state before secured.

FIG. 23 is a perspective view with a magnified section of still anotherpreferred embodiment of a joint construction of a front section and arear section; and

FIG. 24 is a schematic flow diagram illustrating an exemplary processfor manufacturing the first embodiment of the absorbent article inaccordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 through 3 illustrate one embodiment of a tapeless absorbentarticle in accordance with the present invention In the drawings,reference numeral 1 indicates a main body which comprises a frontsection 1A and a rear section 1B. These sections are joined to eachother by suitable bonding means such as heat-bonding to form sidesecurement regions 2a in opposite side regions of the article and in acrotch securement region 2b in a crotch region of the article. The mainbody 1 includes a waist hole 3 and a pair of leg holes 4. An elasticwaist gather 5 is disposed along the periphery of the waist hole 3. Anelastic leg gather 6 is disposed along the periphery of each of the legholes 4.

As illustrated in FIG. 2, each of the front section 1A and the rearsection 1B each comprises a topsheet 11 formed of liquid permeable andhydrophobic material, i.e. a hydrophobic non-woven fabric, a backsheet12 formed of liquid impermeable material, and an absorbent body 13interposed between the topsheet 11 and the backsheet 12.

It is to be understood that the topsheets 11, the backsheets 12 and theabsorbent bodies 13 are separately disposed, respectively, between aboundary between the front section 1A and the rear section 1B. The frontsection 1A and the rear section 1B are independent from each other untilthey are integrally joined to each other in securement regions 2a, 2b.

The absorbent article of such structure includes the main body 1constructed by joining the initially separate, front and rear sections1A, 1B in the securement regions 2a, 2b. Therefore, it becomes possiblethat the front section 1A and the rear section 1B may use differentmaterials for any of their respective topsheets 11, backsheet 12 andabsorbent bodies 13. This permits the front and rear sections 1A, 1B tofunction differently or individually.

In a particular embodiment, the absorbent body 13 of the front section1A comprises a highly absorbent element containing, a combination ofpulps and super absorbent materials generally referred to as "SAP" andthe absorbent body 13 of the rear section 1B comprises a thin andexpansive absorbent element, so that the front and rear sections canserve as a urine spot and a fecal spot, respectively.

It is possible to exhibit an optimum urine absorbent capacity and thecapacity of treating fecal material thereof as mentioned above, when atopsheet of a hydrophobic fine-mesh sheet treated to be hydrophilic isused for the front section 1A, and a topsheet formed of a hydrophiliccoarse mesh sheet is used for the rear section 1B.

FIGS. 4 through 6 illustrate a second embodiment of the absorbentarticle in accordance with the present invention. The absorbent articleincludes a front section 1A as constructed similarly to the frontsection of FIGS. 1 through 3, and a rear section 1B which comprises anelastic composite sheet 21, as will be hereinafter described, and anabsorbent pad 22 disposed inwardly of the composite sheet. Asillustrated in FIG. 5, the absorbent pad 22 is rectangularly configuredand is sealed at its peripheries to enclose an absorbent core 24 withina pouch-like cover 23. The absorbent pad 22 is at its one peripheryjoined to the elastic composite sheet 21 by suitable means such asheat-bonding. The same reference numerals are used throughout FIGS. 1through 6 to indicate the same or similar elements to minimizeredundancy in the explanation thereof.

The elastic composite sheet 21 as is employed to construct the rearsection 1B is illustrated in FIG. 7. The elastic composite sheetcomprises a heat-sealable, film or non-woven elastic sheet 31 formed ofsynthetic rubber, polyurethane, styrene-butadiene block polymer orpolyolefin elastomers, and a non-woven fabric 32, 33 heat-bonded to atleast one surface (to both surfaces in the illustrated embodiment) ofthe elastic sheet 31 by a plurality of parallel securement lines 34. Thenon-woven fabric, 32, 33 provides soft touch to a human skin Preferably,the elastic composite sheet includes a plurality of channel-like spaces35 defined between the elastic sheet 31 and the non-woven fabric 32, 33.

The absorbent article of such construction can be smoothly applied toand removed from a human body since its rear section 1B comprises thehighly elastic composite sheet 21, and is capable of snugly fitting toany human body profiles and of following any movements of the human bodyso that it provides better comfort to users during use.

FIGS. 8 through 11 illustrate a third embodiment of the presentabsorbent article. In the illustrated embodiment, side panels 41a areconnected to a front section 1A to respectively extend from oppositeside ends of the front section 1A. Likewise, side panels 41b areconnected to a rear section 1B to respectively extend from opposite sideends of the rear section 1B. The elastic composite sheet is duallylayered to form each of the side panels. Leading ends of the side panels41a are joined to respective leading ends of the side panels 41b toconnect the front section 1A and the rear section 1B.

A waist elastic 5 is interposed between the topsheet 11 and thebacksheet 12 to form a waist gather disposed along a waist hole 3. A legelastic 6 is attached to each of the side panels 41a, 41b.

Because side panels 41a, 41b are elastically stretchable andcontractable, they are capable of elastically cooperating with theelastic waist portion disposed along the waist hole to facilitateapplication and removal of the article and provide improved fit thereofto the human body during application.

FIGS. 12 and 13 show a fourth embodiment of the present absorbentarticle. In this embodiment, a front section 1A is assembled similarlyto the first embodiment as illustrated in FIG. 3 to comprise a backsheet12, a topsheet 11, an absorbent body 13, a waist gather 5 and leggathers 6. In addition to such elements, a rear section 1B furtherincludes cuff barriers 51a, 51b. These cuff barriers 51a, 51b maycomprise the elastic composite sheet as illustrated in FIG. 7. Each ofthe cuff barriers 51a, 51b extends laterally from a side edge of therear section 1B toward a center of the rear section to cover thetopsheet 11 of the rear section 1B. Leading ends of the cuff barriersare respectively contoured to define an opening 52 therebetween.Accordingly, the topsheet 11 and the cuff barriers 51a, 51b of the rearsection 1B define therebetween a pocket communicating with outsidethrough the opening 52 for containment of fecal material.

FIGS. 14 through 16 illustrate a fifth embodiment of the absorbentarticle in accordance with the present invention. In this embodiment, afront section 1A and a rear section 1B may be respectively assembledsimilarly to those of the first embodiment of FIG. 3 to respectivelyinclude a backsheet 12, a topsheet 11, an absorbent body 13, a waistgather 5 and a leg slather 6. In addition, an absorbent pad 60 ofrelatively small size is attached to the securement region of the frontand rear sections 1A, 1B. The absorbent pad 60 comprises a liquidpermeable, rectangularly shaped pouch-like cover 61 and an absorbentcore 62 enclosed in the cover 61, and is at its one end joined to thesecurement region of the front and rear sections 1A, 1B.

In FIG. 15, the absorbent pad 60 is illustrated to sit on the topsheet11 of the front section 1A. This configuration helps exhibit absorbentcharacteristics particularly suitable for diapers for males. Theabsorbent pad 60 may be moved to sit on the rear section 1B to provideanother configuration more suitable for diapers for females.

As described above, one of the important features of the presentinvention is that separately assembled front and rear sections arejoined to each other in a crotch region and side regions of the article.Generally, the crotch region of the absorbent article is a spot forreceiving a majority of body exudates during a normal use thereof.Therefore, an absorbent capacity and a liquid-sealing characteristics ofthe article in the crotch region is one of the critical factors indetermining performance of the absorbent article. Since the securementregion of the front and rear sections 1A, 1B is located in the crotchregion of the present absorbent article, it is important to assuresufficient liquid-sealability of the article in the crotch region.

The absorbent article suitable for actual use may be obtained whenheat-sealable materials are used to form a topsheet and a backsheet.However, in the event that materials for use are difficult forconventional bonding means to effect liquid-tight sealing thereto, or inthe event that absorbent articles for certain use require more highlyliquid-tight crotch construction, particular designs may be employed tojoin the front and rear sections to form the crotch region.

FIG. 17 shows a particular joint construction which provides a highlyliquid-tight crotch region of an absorbent article. In FIG. 17, atopsheet 11 and a backsheet 12 of a front section 1A of the article areat their respective crotch ends placed upon each other to define a tab71A. Similarly, a topsheet 11 and a backsheet 12 of a rear section 1B ofthe article are at their respective crotch ends placed upon each otherto define a tab 71B. Those tabs 71A, 71B are first positioned in aconfronting relationship, with hotmelt adhesives 72 being carried on theconfronting faces thereof, and then heat-bonded to each other by asecurement line 73. Such a joint constriction provides highlyliquid-tight characteristics at a boundary between the front section 1Aand the rear section 1B so that liquid leakage is prevented under anyuse conditions of the article.

As illustrated in FIG. 18, a reinforcing member 74 may be additionallyprovided and secured along a boundary line between the front section 1Aand the rear section 1B to provide improved leakage protection andimproved strength against tearing.

FIG.19 shows an alternative embodiment of the joint construction of FIG.17 which also provides a highly liquid tight property. In FIG. 19, thetabs 71A, 71B are faced toward each other with a separator 75therebetween. The separator 75 may be formed of a flexible film,preferably of a heat-sealable film or non-woven fabric. The separator 75is interposed between and heat-bonded to the tabs 71A, 71B carryingadhesives 72 such as hotmelts by a securement line 73. An end portion ofthe separator extends upwardly from the topsheet 11 to define aprojection 75a. The projection 75a partitions the article into front andrear portions and serves as a separating petal which functions toeffectively separate urine from fecal material as described above.

As will be readily appreciated, any materials or any combinations ofconstructions enabling the front section 1A and the rear section 1B tofunction individually as illustrated in the above embodiments are merelyexemplary and can be optionally selected in accordance with requirementsby varieties of usages or applications.

Furthermore, when the backsheets of front and rear sections arerespectively formed of films with different colors or patterns, itbecomes easy for users to identify the front and rear portions of thearticle at a glance.

FIGS. 20 through 23 show an absorbent article of the present inventionwhich includes leg gathers. Similarly to the above embodiments, thearticle includes a main body comprising a front section 1A and a rearsection 1B which are joined to each other by tabs 2b. In thisembodiment, the article has first gathers 81 each comprising an elasticstrip member and second gathers 82 each disposed inwardly of therespective first gather and comprising a strip member. The first gathers81 and the second gathers 82 respectively extend along the leg hole 4 ofthe article. For convenience, the first gathers and the second gathersare hereinafter referred to as outer leg gathers and inner leg gathers,respectively. The outer leg gathers 81 can be optionally omitted. Insuch an event, the inner leg gathers also serve as the outer leggathers.

Each of the inner leg gathers 82 comprises a strip member formed ofsuitably flexible material and extends longitudinally across a crotchregion of the absorbent article. The inner leg gathers 82 are laterallyspaced from each other a predetermined distance to define a containmentzone therebetween for absorbing or holding exudates therein. The stripmember is at its one side end joined to an exposed surface of thetopsheet 12 to form each of the inner leg gathers 82.

In accordance with one important feature of the present invention, eachof the inner leg gathers 82 stands up from the topsheet II of the mainbody I at a suitable angle during use of the absorbent article. In thefollowing embodiments, the standing feature of the inner leg gather 82is effected by shortenings the length dimension of a second end(hereinafter referred to as "a distal end") remote from the topsheet 11with respect to the length dimension of a first end (hereinafterreferred to as "a proximal end") joined to the topsheet 11.

In a particular embodiment as illustrated in FIGS. 21A, 21B, 21C, theinner leg gather 82 is tucked in the crotch region of the main body Ialong folding lines which extends divergently and upwardly from theproximal end toward the distal end and for securement so that across-over flap 82a of substantially triangular shape is formed.

While the secured cross-over flap 82a may be formed by tucking the innerleg gather either inwardly or outwardly, it is preferred from viewpoints of product appearances and its other utilities to tuck the innerleg gather inwardly so that the cross-over flap extends inwardlytherefrom.

The extent of the inclination of the gather 82 is selectively determinedby the extent of shortening of the distal and with respect to theproximal end of the strip member. Referring to FIG. 21B, three foldinglines are formed to extend upwardly from the proximal end toward thedistal end of the strip member. The outer and inner folding lines extendupwardly in a diverging relationship toward each other so that twotriangles T1, T2 are defined. These two triangles T1, T2 are defined tobe symmetrical with respect to the intermediate folding line L1. Each ofthe triangles T1, T2 includes the folding line L1 which bounds the twotriangles, a line L2 which extends along the distal end of the stripmember, and a folding line L3 which traverses the strip member at asuitable angle with respect to the folding line. These two triangles areplaced upon each other for securement to form the cross-over flap 82a asabove mentioned.

FIG. 21C shows a triangle T defined by the cross-over flap 82a. In FIG.21C, reference numeral L0 indicates a base line which corresponds to atop surface of the topsheet 11 to which the cross-over flap 82a isattached. The line L3 of the triangle T defined by the cross-over flap82a is inclined by a predetermined angle θwith respect to the base linetopsheet) L0. The angle θof inclination becomes greater as the lengthdimension of the line L2 of the triangle T increases. As the anglebecomes greater, a top of the cross-over flap 82a is further spaced awayfrom the topsheet 11 and is moved further upwardly.

Although it is not required that the cross-over flap 82a ofsubstantially triangular shape is secured to any other members, it maybe secured to the topsheet 11 inwardly of the inner leg gather 82. FIG.22 shows one embodiment of the absorbent article during use whichincorporates the cross-over flap therein. By this construction, thecrossover flap 82a acts to pull the inner leg gather 82 inwardly in thecrotch region against the force (shown by an arrow X in the drawing ofFIG. 23) exerted by the leg action of a user which acts to pull out theinner leg, gather 82 from the leg hole 4. Therefore, the provision ofthe cross-over flap serves to prevent such an inconvenience from takingplace when the construction is applied to the tapeless absorbent articlewherein the user inserts a leg into a leg hole 4 from inside of thearticle.

In an actual production of the absorbent article of the presentinvention, it is possible to use the procedure set out below. Asillustrated in FIG. 22, in a stage prior to securement of the front andrear sections 1A and 1B together at a joint portion 10, the stripmembers for forming the inner leg gathers 82 are connected at theirlower edges to the topsheets 11, respectively. Layers 83 of an adhesivematerial such as of hot-melt-type are applied on the side facing,together of each pair of the strip members over a suitable length. Thetopsheets 11 of the front and rear sections 1A and 1B are then forced tocontact to each other in the direction of an arrow Al, thereby to bondthe strip member pairs by the adhesive layers 83.

As a result, each pair of the strip members are connected together toform the continuous leg gather pair 82. Each of the leg gathers 82 thusformed is connected to the topsheet 11 at its lower edge, and at thejoint portion 10 the upper edge is also connected to the topsheet. Inthis construction, the upper edge of each leg gather is longer than thelower edge, thereby to stand up the leg gather when the absorbentarticle is applied to the wearer's body.

Now the explanation is made with reference to FIG. 24 regarding oneexemplary method of manufacturing absorbent articles as illustrated inFIGS. 1 through 3. In accordance with this method, a first step ofassembling the front section is performed simultaneously with a secondstep of assembling the rear section. The subsequent third step involvesjoining the individually assembled front and rear sections.

First, the first step which assembles the front section will beexplained. Referring to FIG. 24, a first sheet 101 comprising acontinuous web is continuously withdrawn from a roll 102 at apredetermined constant speed. Meanwhile, a carrier sheet 104 iscontinuously withdrawn from a roll 103. A pulp former 105 treatsabsorbent materials such as pulp to feed preformed absorbent bodies (notshown) of predetermined shape to place them onto the carrier sheet 104at predetermined intervals. The first sheet 101 is then placed upon thecarrier sheet 104 carrying the absorbent bodies to form a first assembly100.

An elastic leg material 109 withdrawn from a roll 108 is attached to asecond sheet 107 which is in turn withdrawn from a roll 106 by bondingmeans which is not shown in the drawing. The second sheet 107 carryingthe elastic lee material is subsequently placed upon the first sheet 101and the absorbent bodies. A waist gather material 111 withdrawn from aroll 110 is placed on a bottom side of the first sheet 101 which is thentransferred to a next step.

The second step of assembling the rear section is performed likewise thefirst step. A second sheet 201 comprising a continuous web iscontinuously withdrawn from a roll 202 at a predetermined constantspeed. Meanwhile, a carrier sheet 204 is continuously withdrawn from aroll 203. A pulp former 205 treats absorbent materials such as pulp tofeed preformed absorbent bodies (not shown) of predetermined shape toplace them onto the carrier sheet 204 at predetermined intervals. Thesecond sheet 201 is then placed upon the carrier sheet 204 carrying theabsorbent bodies to form a second assembly 200.

An elastic leg material 209 withdrawn from a roll 208 is attached to asecond sheet 207 which is in turn withdrawn from a roll 206 by bondingmeans which is not shown in the drawing. The second sheet 207 carryingthe elastic leg material is subsequently placed upon the second sheet201 and the absorbent bodies. A waist gather material 211 withdrawn froma roll 210 is placed on a bottom side of the second sheet 201 which isthen transferred to a next step. However, the positional relationship ofthe second sheet 201, the carrier sheet 204, the absorbent body and thewaist gather material 211 is reversed from that of the first assemblywith respect to the first sheet 101.

In the above embodiment, the first sheet 101 comprises a non-wovenfabric which forms a topsheet and the second sheet 201 comprises aliquid impermeable film which forms a backsheet.

The first assembly 100 and the second assembly 200 as manufactured viathe above steps are then placed upon each other so that the absorbentbodies thereon face toward each other, and are subsequently introducedinto a supersonic sealing equipment 301 where they are heat-bonded toeach other along, a crotch region and side regions of the resultingarticle. It is important in this step to assure that the first assembly100 and the second assembly 200 are correctly aligned with each other.This alignment can be readily effected by synchronizing the feed speedsof the assemblies 100, 200.

After the heat-bonding is completed, cutting is effected by a roundcutter 302 to form the leg holes, and subsequent cutting by an endcutter 303 separates the bonded assemblies into individual articlepieces.

In order to manufacture the absorbent article as illustrated in FIG. 8which joins the respective side ends of the front and rear sections bythe elastic side panels 41a, 41b, the elastic strip members comprisingthose side panels 41a, 41b may be previously attached to opposite sideends of each of the first and second sheets 1A, 1B such as byheat-bonding before distal ends of the respective strip members areheat-bonded to each other by the supersonic sealing equipment 301.

Alternatively, the elastic waist portion 5 may be dimensioned so thatits opposite side ends extend outwardly from respective side edges ofeach of the front and rear sections to define the side panels 41a, 41b.

As described above, the absorbent article in accordance with the presentinvention comprises the front and rear sections which include individualtopsheets, backsheets and absorbent bodies, and are joined to each otherby suitable bonding means such as heat-bonding at a crotch region andopposite side regions of the absorbent article. This permits the frontand rear portions of the absorbent article to function differently fromeach other so that the present absorbent articles are able to beresponsive to various needs including various configurations for use.

Furthermore, in accordance with the present method, the front and rearsections are separately assembled before they are finally bonded to eachother to form a final product. Therefore, the present method is able toeliminate the conventional folding step in which the topsheet andabsorbent body assembly are folded along a crotch region, andaccordingly to eliminate necessity of the troublesome alignment of sideends thereof during the folding step. As a result, the present methodprovides a greatly reduced rate of product loss and facilitates anoverall process control.

We claim:
 1. An absorbent article comprising:a main body having a waisthole and a pair of leg holes, a crotch region between the leg holes,opposite side regions, an elastic waist portion disposed along saidwaist hole, and a leg gather disposed along each of said leg holes; saidmain body comprising separately produced front and rear sections, saidfront section comprising a first backsheet formed from material suppliedfrom a first backsheet web, a first topsheet formed from materialsupplied from a first topsheet web, and a first absorbent bodyinterposed between said first topsheet and said first backsheet, andsaid rear section comprising a second backsheet formed from materialsupplied from a second backsheet web, a second topsheet formed frommaterial supplied from a second topsheet web and a second absorbent bodyinterposed between said second topsheet and said second backsheet, saidseparately produced front and rear sections being joined so that theirrespective topsheets face each other and are bonded to each other in thecrotch region and opposite side regions of the article.
 2. The absorbentarticle of claim 1, whereinsaid front and rear sections respectivelyhave portions extending laterally outwardly from the absorbent body andsecured in facing relation to each other in said crotch and oppositeside regions of the article.
 3. The absorbent article of claim 1,whereinsaid leg gather comprises a member disposed on a top surface ofeach of said front section and said rear section, said member having aproximal end disposed adjacent to said top surface and a distal endspaced away from said top surface, said member being secured onto itselfat a location adjacent to the crotch region where said front section andrear section are bonded to each other.
 4. The absorbent article of claim1, whereinsaid backsheet of the rear section is comprised of anelastically stretchable and contractible material.
 5. The absorbentarticle of claim 4, whereinsaid elastically stretchable and contractiblematerial comprises an elastic composite, said elastic composite isformed from a liquid impermeable, elastic material and a non-wovenfabric, said liquid impermeable, elastic material comprising said secondbacksheet and said non-woven fabric comprising said second topsheet. 6.The absorbent article of claim 2, whereinsaid portions are secured toeach other by hotmelt adhesives.
 7. The absorbent article of claim 1,whereinsaid front section and rear section have tabs at their respectiveends, adjacent the crotch region and said tabs are secure to each otherby hotmelt adhesives, said article further having a reinforcing membersecured in the crotch region and extending along a boundary line betweensaid front section and said rear section.
 8. The absorbent article ofclaim 1, whereina projecting separator petal is disposed along aboundary line between said front section and said rear section in saidcrotch region for separating solid exudates from liquid exudates.
 9. Theabsorbent article of claim 1, whereinsaid front section and said rearsection are joined to each other by elastic side panels attached torespective opposite sides of the front and rear sections.
 10. Theabsorbent article of claim 1, whereinsaid rear section further comprisesa barrier cuff spaced away from the topsheet to define a spacetherebetween, said barrier cuff having an opening for receiving exudatesinto said space.
 11. The absorbent article of claim 1, whereinanabsorbent pad is disposed between said front section and said rearsection, said absorbent pad is joined at one end to a securement regionof said front and rear sections so that the absorbent pad is movablebetween a first position on the topsheet of the front section and asecond position on the topsheet of the rear section.
 12. An absorbentarticle comprising:a main body having a waist hole and a pair of legholes, a crotch region between the leg holes, opposite side regions, anelastic waist portion disposed along said waist hole and leg gathersdisposed along each of said leg holes; said main body comprisingseparately produced front and rear sections, each of said front and rearsections comprising a backsheet formed from materials supplied fromrespective first and second backsheet webs, a topsheet formed frommaterials supplied from respective first and second topsheet webs, anabsorbent body interposed between said topsheet and said backsheet, saidseparately produce front and rear sections being joined so that theirrespective topsheet face each other and are bonded to each other in thecrotch region and opposite side regions of the article, said frontsection having at least one constituent element whose property isdifferent from that of the corresponding element of the rear section,and said leg gather of each of said front and rear sections being at anend secured onto itself in the crotch region of the main body to definea cross-over flap of substantially triangular shape extending inwardlyof said leg gather so that said leg gather stands up from the topsheet.